Mbongeni Mbonambi's try right at the end consigned France to defeat after they led South Africa by 14 points in Paris.
Sean O'Brien suffered another injury blow on Saturday, but Ireland coach Joe Schmidt says he has the resilience to make a quick return.
Stuart Hogg said the time has come to challenge himself in a different environment after nine seasons with Glasgow Warriors.
Wallabies and Waratahs back-rower Jack Dempsey re-signed until at least 2020.
Kieran Marmion should be fit to feature in Ireland's upcoming match against New Zealand, but Sean O'Brien will play no part.